Mining-tool.



J. POLLOCK.

MINING TOOL.

APPLIOATION FILED OGTA, 1909.

flo

JAMES PoLLocx, or NEW YORKQN. Y.

mrmnroon.

Specification o fLetters Patent.

Patented Jan. 10, 191.1.

Application ledlOctober 4, 1909. erial No. 520,862.

To aZZ 'whom it mag/concern.'

Be it known that I, JAMES PoLLoCK, a citizen of the yUnited States, residing in the borough of Brooklyn of the city of New York, in the State of New York, have invented certain new and useful Improvements in Mining-Tools, of which the fol` v pose of forming at the inner end of the hole drilled to receive the charge of explosive a laterally enlarged chamber in order that the force of the explosion may be so directed as tobe more effective in breaking down the coal, especially inthe working of comparatively thin seams.

The invention will be more fully eX-' plainedhereinafter with reference to the -accompanying drawings in Which- Figure l is a View, partly in longitudinal section and partly 'inelevatiom of the im proved tool. Fig. 2 isa detail view iny section, on the plane indicated by the line 2 2 of Fig. l, but onv alarger'4 scale. Fig. 3 is a view showing the tool 1n working position'.l

In ythe mining of coal in comparatively thin seams, there is drilled into the coalbody a from the face b a generally cylindrical hole c of suitable depth and diameter. Then the inner or farther end of this hole is' spread or expanded or mushroomed by the improved too, as indicated at'd, in Fig. 3, so as to provide a large area of surface against which the force ofthe explosion of the powder or other explosive used may be exerted. The effect of explosion of the powder when spread out in the chamber d is to blow out the .coal from the'breast on lines which diverge from the chamber d toward'l the face of the working. Each charge, the force of which is mainly directed toward the face of the Working, therefore breaks down more coal than would a similar charOe placed at the inner end of a cylindrical hole, and moreover has less tendency to pulverize the coal.

The improved tool for the inner end of the hole comprises a body l1, adapted-to lit freely Within the cylindrical hole which is first drilled'into the coal body and toenter to or nearly to the bottom ofthev same, and" g as byl a ring la,

Figs. .l and 3 an air hose o may a cut-ter 2' which can be extended laterally as the tool is rotated, suitable means being provided for support-ing and rotating the tool. As shown, the body it is composed' of two half cylinders ZL 'and /z-f, so that they y.

may be properly ch'ambered internally, as

at h3, to support firmly the cutting tool. The two parts may be held firmly together, threaded upon aprojecting hub la# at one end, and byaf tube Z which is threaded upon a similar projecting hub h5 at the other end and forms the shank of the tool. l.Within the chamber it? of the body /L is mounted a plunger m which is adapted to be moved` longitudinally within the body,

as by awrod n which is threaded, as at a', l

ina cap Z secured to the outer end of the tube Z, and is provided with a hand wheel' n2.

The shank or bar z" upon which the cutter z' is mounted is curved in the arc of a circle` and is connected to the plunger in, as byv a pin and slot connection?, so that by the movement of the plun er in the chamber' h3 the cutter may be with rawn Within the'body la, as shown in full lines in Fig. l, or extended laterally, as indicated by dottedl lines' in the'same figure, the cutter and its shank projecting from the body '7L through an opening 11,, provided therefor While the shank has rigid bearings against the wall of the chamber 71,3 and on the walls vof the opening 1,. The chamber h3 within the body L is of such dimensions as to permit the curved shank orybar to move `in the arc of a circle within the body. The tool is rotated as the cut-ter is gradually extended and for this purpose the tube Z,`to whicht-he body [Lis secured, may be pjrovided with a gear Z2 driven by any suita le means, as by a motor Z3, as indicated in Fig. 3.V For clearing out the hole lmade by the cutter as it is formed air under pressure from the usual compressed air supply isdirected into the hole. As shown 1n be connected to a jacket o swiveled on'the tube Z and having -an annular chamber o2 from which air may be admitted to t-he interior of the tube Z through ports o3.l From the tube Z' the air passes throu h channels 04 in the end ofthe body 71 into t e chamber 71,3 within the body, from which it escapes through a port oi which is properly placed to direct the air into the hole as it is formed by the cutter .in the coal body. The cutter bodyh is spi- Arally grooved externally, as at p, and the tubo -the tool h is introduced and thel cutter i 1s gradually extended laterally as the tool is y rotated, until the hole d has been expanded or mushroomed to the desired extent; The cutter z' is t'hen drawn back within the body of the tool and the tool itself is Withdrawn from the hole so that the chamber` CZ may be ed for longitudinal movement ber of the body lilled with the explosive.

I claim as my invention:

l. A tool for mining, comprismg a body l adapted to be introduced into a previously formed hole and to be rotated therein, said body beino formed intwo longitudinal parts chambered internally, said parts being ex# tended tovform hubs one at each end of the body, a ring `engaging the Ahub at the forwardend of the body, atube threaded upon the hub at the other end of the body and forming the shank of the tool, abar curved in the are 'of a circle'and carryin a cutter, said bar being mounted and guide ing said body for movement in the arc of a circle toextend the cutter laterally from the body, a plunger adaptin the chamand operatively connected to said bar, and means to move said plunger.

2. A tool for mining, adapted to be introduced into a previously formed hole and to be rotated therein, said body bein formed in two longitudinal parts chambere internally, a ring securin said parts together at one end, a tube sma ler in diameter than the body and securing said -partstogether at the other end Aand Jforming the shank of the tool, a bar curved in the arc comprising a body y of av circle and supported and guided by said I body for movement 1n the are of a clrole and carrying a cutter and a rod extended through said tube and operatively 'connected with said bar to extend the same, said body being formed externally with a spiral groove and said tube being provided externally .with a spiral web.

This specification signed and witnessed I1 this th day of September, D. 1909.

JAMES PoLLooK.

Signed in the presence. of-

AMBRosE L. OSHEA, ELLA J. KRGER. 

